Prepare a 200X Luciferin stock solution (30 mg/ml) in sterile water. Mix gently by inversion until Luciferin is completely dissolved. Use immediately, or aliquot and freeze at -20 °C for future use.

Note: One can either reconstitute the entire 1.0 g of D- Luciferin in 33.3 mL of sterile water to make the 30 mg/mL (200x) stock solution, or reconstitute the quantity of D-Luciferin necessary for an individual experiment.

Prepare a 150 μg/mL working solution of D-Luciferin in pre-warmed tissue culture medium.